Facile and rapid ruthenium mediated photo-crosslinking of Bombyx mori silk fibroin.

A facile and rapid ruthenium catalysed photo-crosslinking method was employed to prepare Bombyx mori silk fibroin hydrogels for the first time that may be used for biomedical applications. The gels have been characterised by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), photo-acoustic Fourier transform infrared spectroscopy (PA-FTIR), and X-ray diffraction (XRD). We have reported the tuning of the properties of the chemically crosslinked gels through hydration level. DSC and DMA measurements have shown that the molecular chain dynamics and mechanical properties are dependent on the moisture/water content. The structural changes upon gelation were examined through the use of DSC, PA-FTIR and XRD, which confirmed that the gels were less crystalline than the original silk powder. Finally, the biocompatibility and hence, the potential tissue engineering application of the silk fibroin hydrogel was also assessed by culturing chondrocyte progenitor cells for up to one week on the engineered fibroin surfaces.